Reply by PurpLev

metal is preferred because it has less friction (air and debris), but if PVC is only available to you or more affordable, it will work just fine.

no need for double wall. the thinner walled pipes will work just fine – you are not creating a vacuum here, just passing a lot of air through them (think of straw – as thin as it’s walls are – as long as it’s open on both sides it will not collapse regardless of how much air you blow/suck through it)

no you do not NEED to ground PVC, but you CAN if you encounter static shocks often when working near it.. for starters I would stay away from grounding and adding interference to the airflow.